Monday, October 10, 2011

Goalie Effects on the Jack Adams Award

Last week Hockey Prospectus asked me to predict the 2011-12 award winners as part of its ongoing season preview. I usually just throw out names for that kind of thing because it's a pure guess anyway, and to be honest I'm not at all sure that I know much more than the next guy about who is going to be this year's best rookie or best defenceman or best coach.

Anyway, for Jack Adams I filled in Guy Boucher's name after not much more than a few seconds of thought about it. I figured he did a pretty good job last year and attracted lots of attention during Tampa's run to the Conference Finals, and if the Lightning finish with another 100+ point season maybe people would write his name down on their ballots.

Not too long afterwards, there was an insightful comment on Coppernblue by dkball7: "DeBoer should be everyone's pre-season pick for Jack Adams. As long as the team's PDO regresses to 100%, he will look like a genius."

In hindsight, it makes sense that I should not have picked a coach on a team that performed well the year before, like Boucher's Lightning, but should instead have picked one on a team that underachieved, like DeBoer's Devils. The Coach of the Year often goes to a candidate on a team that massively improved relative to the year before, which often is caused in large part by a significant swing in percentages from one year to the next.

I looked at the teams for each of the Jack Adams award winners since 1990, and compared each team's performance during the year where their coach picked up his hardware to the team's performance during the year prior and the year following. Here are the percentages, with everything adjusting to an average level of 10.0% shooting/.900 save percentage:

Only one out of 21 of the teams that produced a Jack Adams award winner posted a below-average save percentage during that season. In contrast, during the prior year, 13 out of those 21 teams had a below-average save rate. During the year after, the goaltending still remained strong for the most part, with just three teams dropping back to below-average save numbers.

The following year numbers imply that either the teams had slightly above average shooting and goaltending talent as a whole, or the award-winning coaches themselves combined for a positive effect on the team's numbers.

I think the goaltending numbers in the year after are more likely to reflect goalie talent than the coach's system of play. There were a number of top goalies represented (e.g. Hasek, Brodeur, Luongo, Thomas). Overall, the goalies had an average career save percentage of .906 over a period where the league average save percentage was .902. Considering that some of their careers stretched back further than 1989-90, when the league average was even lower, it seems reasonable that the combined goalies were about .005 better than league average, although it should be at least noted that some of the coaches in the sample have been known to affect shot quality, particularly guys like Burns and Lemaire, which may account for a small part of the above-average result.

It is interesting that many of the teams had the same goalie during the Jack Adams year as they did the season before. Eleven of 21 teams had the same starting goalie, with all of them playing a relatively similar number of games as well. Here are the save percentage numbers for the season prior, during and after, split out by whether the team had the same netminder as the year before (numbers adjusted again to league average with a baseline of .900):

Same goalie: .901, .909, .907

New goalie: .893, .909, .904

The largest improvements came for teams that brought in new goalies, obviously, but a good goalie coming off of an average season can also have a big impact in improving a team's fortunes and getting his head coach some extra attention.

The numbers do suggest that a lot of things simply went right for coaches during their winning years, but I certainly don't want to imply they had no effect at all. There is, for example, the shots for and against evidence, which shows that the teams also had a substantial improvement in their underlying possession metrics during the Jack Adams winning years. Teams playing for a Jack Adams winning coach were also more disciplined than average, as well as more disciplined compared to the year before.

Prior to Jack Adams Year: 1.005 SF/SA ratio, 362 PPOA

During Jack Adams Year: 1.064 SF/SA ratio, 340 PPOA

Following Jack Adams Year: 1.044 SF/SA ratio, 350 PPOA

Goaltending and shooting luck do not determine everything, but a lot of what the best coaches do is difficult to judge and rate, especially from a distance. For that reason, exernal factors can often come into play. As the old hockey saying goes, "Show me a good coach and I'll show you a great goaltender."

In summary, if you want to maximize your chance of being named the NHL's best coach, you should try to get a job on a team that either had awful goaltending the season before and made a move to address that weakness, or where a good goaltender had a down year. Either one of those scenarios would give a coach the best chance to see his team's percentages swing around in a hurry, leading to a significant improvement in the standings. That will in turn cause many people to think there must have been some coaching magic at work, and if you're lucky the awards recognition will soon follow.

To make a better Jack Adams prediction, we should apply this logic to this year's teams, and find a team with good goaltending that had weak goaltending last year and is likely to improve in the standings. The Flyers and Caps brought in new top-flight goaltenders, but both actually had pretty good save percentages last season. Several other teams have also improved in net but are still expected by most to finish near the bottom of the league and as a result are unlikely to produce a Jack Adams winner (Islanders with Nabokov, Senators with Anderson, Avalanche with Varlamov).

There are five teams that had subpar goaltending last season as well as overall PDOs below 100 that could be primed to do better in 2011-12:

New Jersey: 7.3 SH%, .906 Sv%

Toronto: 9.0 SH%, .907 Sv%

Tampa: 9.3 SH%, .903 Sv%

St. Louis: 9.5%, .902 Sv%

Columbus: 8.4%, .900 Sv%

Guy Boucher's Lightning show up on this list, suggesting that my random intuition may not have made that bad of a pick after all. There has to be some concern, however, for the fact that starter Dwayne Roloson is turning 42 next week. That said, he should still be better than the combo of Mike Smith and Dan Ellis (.894 last season), and Mathieu Garon will also provide improved backup goaltending. The Lightning may see their shooting regress slightly, but if they can duplicate last year's outshooting results and if Roloson can hang together to give them better goaltending then they will be definite challengers in the East. That could put Boucher in the conversation for Coach of the Year, but I'm not sure if it would be enough, especially if there is someone else out there who oversaw a much larger improvement in terms of wins and losses.

Age is also a concern for Martin Brodeur, but nobody is expecting a .903 again, and the New Jersey shooters are virtually guaranteed to improve (7.3% is a major outlier for a team shooting percentage). Jaroslav Halak also would be a good candidate for a bounceback year in St. Louis. If James Reimer is the real deal with .920 talent in the NHL he could certainly win Ron Wilson a trophy this year, but that still doesn't look to me like a good bet. As long as Columbus is going to continue to bet all their chips on Steve Mason I'm not sure I'll be expecting above-average goaltending in Columbus, although there likely could be some improvement there, perhaps even enough to get into the playoffs depending on luck and how well the rest of the team plays.

After considering this evidence, I think Peter DeBoer is the best pick for the 2012 Jack Adams, with all signs pointing to the Devils coming back strongly this season. There is always the chance, of course, that a team loses a star player and keeps on trucking, like Pittsburgh did in Dan Bylsma's award-winning campaign, or that one of the league's best teams has a spectacular year and cleans up at awards time, or that a team with a lot of new additions like Buffalo really comes together and climbs the standings. At the end of the day, the most likely winner is probably the coach who saw the largest improvement from the year before, and for this season the team with the best chance to improve is almost certainly the New Jersey Devils.

2 comments:

One thing I found when I looked at ~15 years of JA winners in 2004 (http://hfboards.com/showthread.php?t=73772) was, in addition to touching on the save percentage thing, was you can safely predict that a JA-winning coach will be turfed within a year or two. If they haven't won it within three years of starting with their team, they likely won't ever (call it the Trotz/Ruff Syndrome).

Small sample sizes to be sure, but if Boucher or DeBoer win it in 2012, I'd bet even money they'll be looking for a new team by 2014.

About Me

I'm Philip Myrland, goalie stats blogger since 2007 and former writer for Hockey Prospectus. I call myself a contrarian because I rely mainly on stats-based analysis, think large sample sizes are more important than "big saves" and prefer to rank goalies based on save percentage rather than team success. In other words, pretty much the mainstream views of the hockey analytics community, but I've grown attached to the handle and plan to keep it as long as broadcasters everywhere keep bringing up GAA and wins. If you have any questions or comments contact me by email (contrariangoaltender@gmail.com). You can also follow me on Twitter (@tcghockey).